const { Map, List } = require('immutable');

let map= Map({a1:{a2:{a3:0}},b1:{b2:{b3:0}}});
let newMap = map.setIn(['a1','a2','a3'],5);
console.log(newMap.getIn(['a1','a2','a3']))

let list = List([1,2,3,]);
let newList = list.push(4);
console.log(list.size)
console.log(newList.size)